146958-06-7

Usage

Uses

Used in Solar Cell Applications:
Formamidinium Bromide is used as a perovskite precursor for the synthesis of FAPbBr3 and mixed halide perovskites (FAPbIyBr3-y). The application reason is that these materials have a tunable bandgap between 1.55 eV and 2.3 eV, which allows for optimization of the band gap, carrier diffusion length, and power conversion efficiency in perovskite-based solar cells.
Used in Tandem Solar Cell Applications:
Formamidinium Bromide is used as a perovskite precursor for FAPbBr3 material, which has an energy bandgap of 2.23 eV. The application reason is that FAPbBr3 is an ideal candidate for tandem solar cell applications due to its suitable bandgap, which enables the extension of the photoexcited species lifetime and enhancement of charge transport through the layer, optimizing the performance of multi-junction solar cells.

Upstream product

• 77287-34-4 formamide 
• 3473-63-0 formamidine acetic acid 

Relevant academic research and scientific papers

Syntheses, Crystal Structures, and Optical Properties of the Hexagonal Perovskites Variants ABX3 (B = Ni, A = Gu, FA, MA, X = Cl, Br; B = Mn, A = MA, X = Br)

Herein we report on our systematic investigations on the solution processed synthesis and characterization of transition metal halides (guanidinium, formamidinium, and methylammonium nickel bromides and chlorides as well as methylammonium manganese bromide) with the composition ABX3 (A = organic cation; B = Mn, Ni; X = Cl, Br). The investigations were carried out with respect to possible applications of 3d transition metal compounds for the perovskite solar cell. All the compounds represent different variants of the hexagonal perovskite structure (2H). Crystal structures and symmetry relations are discussed. Additionally, (CH3NH3)2MnI4, which consists of tetrahedral coordinated Mn2+, and the water containing compounds (CH3NH3)MnBr3·2H2O, which forms chains of edge sharing octahedra, as well as (CH3NH3)NiCl3·2H2O, which consists of dimers of octahedra, are presented. Investigations on the crystal structures are supported by vibrational and optical spectroscopy.

Morphology-Controlled Synthesis of Organometal Halide Perovskite Inverse Opals

The booming development of organometal halide perovskites in recent years has prompted the exploration of morphology-control strategies to improve their performance in photovoltaic, photonic, and optoelectronic applications. However, the preparation of organometal halide perovskites with high hierarchical architecture is still highly challenging and a general morphology-control method for various organometal halide perovskites has not been achieved. A mild and scalable method to prepare organometal halide perovskites in inverse opal morphology is presented that uses a polystyrene-based artificial opal as hard template. Our method is flexible and compatible with different halides and organic ammonium compositions. Thus, the perovskite inverse opal maintains the advantage of straightforward structure and band gap engineering. Furthermore, optoelectronic investigations reveal that morphology exerted influence on the conducting nature of organometal halide perovskites.

Adjusting the Introduction of Cations for Highly Efficient and Stable Perovskite Solar Cells Based on (FAPbI3)0.9(FAPbBr3)0.1

Although the power conversion efficiency (PCE) of perovskite solar cells (PSCs) has increased to 22.7 %, the instability when exposed to moisture and heat has hindered their further practical development. In this study, to gain highly efficient and stable perovskite components, methylammonium (MA), Cs, and Rb cations are introduced into a (FAPbI3)0.9(FAPbBr3)0.1 (FA=formamidine) film, which is rarely used because of its poor photovoltaic performance. The effects of different contents of MA, Cs, or Rb cations on the performance of (FAPbI3)0.9(FAPbBr3)0.1 films and devices are systematically studied. The results show that the devices with Cs cations exhibit markedly improved photovoltaic performance and stability, attributed to the clearly enhanced quality of films and their intrinsic stability. The (FAPbI3)0.9(FAPbBr3)0.1 devices with 10 % Cs show a PCE as high as 19.94 %. More importantly, the unsealed devices retain about 80 % and 90 % of the initial PCE at 85 °C after 260 h and under 45±5 % relative humidity (RH) after 1440 h, respectively, which are better than that with 15 % MA and 5 % Rb under the same conditions. This indicates that a highly efficient and stable perovskite component has been achieved, and PSCs based on this component are expected to promote their further development.

Synthesis and characterization of perovskite FAPbBr3?xIx thin films for solar cells

Abstract: FAPbI3, FAPbBr3, and FAPbBr3?xIx perovskite thin films were produced in a single step from a solution containing a mixture of FAI, PbI2, FABr, and PbBr2 (FA?=?formamidinium). FAPbBr3?xIx perovskite thin films were deposited onto ITO-coated glass substrates by spin coating. X-ray diffraction analyses confirmed that these thin-film perovskites crystallize in the cubic phase (Pm-3?m) for all composition range 0?≤?x?≤?3. Mixed lead perovskites showed a high absorbance in the UV–Vis range. The optical band gap was estimated from spectral absorbance measurements. It was found that the onset of the absorption edge for FAPbBr3–xIx thin films ranges between 1.47 and 2.20?eV for x?=?0 and x?=?3, respectively. Photoluminescence emission energies for mixed halide perovskites were also dependent on their composition and presented intermediate values from 810.4?nm for FAPbI3 to 547.3?nm for FAPbBr3. Graphical abstract: [Figure not available: see fulltext.]

Efficient solar cells with enhanced humidity and heat stability based on benzylammonium-caesium-formamidinium mixed-dimensional perovskites

Perovskite solar cells (PSCs) exhibit remarkable photovoltaic performance with a power conversion efficiency (PCE) over 22%, but they exhibit instability in moist environments and at high temperatures. Compared to 3D perovskites, two-dimensional (2D) layered perovskites display excellent environmental stability but relatively poor photovoltaic performance. Here, we combined 2D/3D perovskites and simultaneously introduced the cesium cation (Cs+) to fabricate benzylammonium-caesium-formamidinium mixed-dimensional (MD) perovskite (BE/FA/Cs MD perovskite) solar cells. The BE/FA/Cs MD perovskite device with an optimal benzylammonium content exhibits a PCE as high as 19.24%. The improved PCE of 19.24% (BE/FA/Cs MD, x = 0.05) is attributed to great crystal orientation, outstanding surface quality, superior optical properties and enhanced charge transfer. More importantly, the BE/FA/Cs MD perovskite devices display superior humidity and heat stability. When subjected to 50% relative humidity (RH) for 1600 h and 85 °C for 240 h in the dark, the BE/FA/Cs MD (x = 0.05) devices without encapsulation retain 85% and 83% of their initial PCE, respectively. These results provide us with an important method to obtain highly efficient MD PSCs with long-term stability as a next-generation photovoltaic energy source.

Solvent-free, mechanochemical syntheses of bulk trihalide perovskites and their nanoparticles

For the first time, we have synthesized APbBr3 (A = Cs+/MA+/FA+, where MA+ = CH3NH3+ and FA+ = CH(NH2)2+) bulk as well as nanoparticles (NPs) by solid-state reactions at room temperature. This facile strategy yields different shape structures e.g. square and rectangular (CsPbBr3), spherical (MAPbBr3) and parallelogram (FAPbBr3) NPs.

HIGHLY TUNABLE COLLOIDAL PEROVSKITE NANOPLATELETS

Colloidal perovskite nanoplatelets can provide a material platform, with tunability extending from the deep UV, across the visible, into the near-IR. The high degree of spectral tunability can be achieved through variation of the cation, metal, and halide composition as well as nanoplatelet thickness.

OPTOELECTRONIC DEVICES WITH ORGANOMETAL PEROVSKITES WITH MIXED ANIONS

The invention provides an optoelectronic device comprising a mixed-anion perovskite, wherein the mixed-anion perovskite comprises two or more different anions selected from halide anions and chalcogenide anions. The invention further provides a mixed halide perovskite of the formula (I) [A][B][X]3 wherein: [A] is at least one organic cation; [B] is at least one divalent metal cation; and [X] is said two or more different halide anions. In another aspect, the invention provides the use of a mixed-anion perovskite as a sensitizer in an optoelectronic device, wherein the mixed-anion perovskite comprises two or more different anions selected from halide anions and chalcogenide anions. The invention also provides a photosensitizing material for an optoelectronic device comprising a mixed-anion perovskite wherein the mixed-anion perovskite comprises two or more different anions selected from halide anions and chalcogenide anions.

Amides as Nucleophiles: Reaction of Alkyl Halides with Amides or with Amides and Water. A New Look at an Old Reaction

Heating of formamide with an alkyl halide (with or without water) affords a mild, nonhydrolytic, high-yield synthesis of alcohols and formate esters.Yet the way in which substitution on the alkyl halide actually occurs remains obscure.To explore this question, thermal reaction of 1-bromooctane (1a) with formamides (HC(O)NHR, R=H, Me; 2a, 2b) was studied quantitatively.Major products are 1-octanol (3) and n-octyl formate (5); minor products are 1-octene (4), di-n-octyl ether (6), and N-octylformamide (7, from 2a, only).Solid coproduct is HC(=NR)NHR + Br(1-) (e.g., 8a, R=H, methanimidamide hydrobromide).Analogously, 1a and N-methylformamide (2b) give alkylated products 3,5, and 6 along with 8b (R=Me). 1-Iodooctane (1b) reacts similarly.Probe samples show that 1-octanol (3) is first formed, followed by 5 and 6.Occurence of 8a-c is key to a mechanistic interpretation of the reaction.An imidate ("salt I"), e.g., from 1a and 2b, is first formed and reacts with amide 2b to give and 3.Now alcohol 3 is converted to ester 5 and 8b by reaction with this same formylamidine.Water, if present, adds to the imidate and gives a new tetrahedral intermediate that cleaves to ester 5 and amide salt, RNH3X.Analogous reaction steps are proposed to generate side products 4, 6, and 7.Alkylation of formamide by C6F13CH2CH2I (1c) is considerably slower and less efficient than alkylation by 1-bromooctane.This result stands in sharp contrast to fast, efficient reaction of 1c with N-methylformamide or with DMF and water.